A Brief Comparative Study on Removal of Toxic Dyes by Different Types of Clay (original) (raw)
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Dyes adsorption using clay and modified clay: A review
Journal of Molecular Liquids, 2018
The effective use of the sorption properties of different clays as sorbents for the removal of dyes from wastewater has currently received much attention because of the eco-friendly nature of clay materials. Dyes are complex class of organic compound having wide range of applications in textile and food industries and a large amount of dyes are wasted, which get mixed in natural water resources. Mixing of dyes in water resources must be prohibited for the safety of natural ecosystem. The adsorbents (natural and modified) have been successfully for the adsorption of dyes form wastewater. This review article highlights the importance of clay (simple and modified) as an adsorbent for the adsorption of dyes from textile wastewater. Appropriate conditions for clay-dye system and adsorption capacities of a variety of clays are presented and sorption process is critically analyzed in this study. Studies reported the clays as an adsorbent from 2004-2016 are included and different properties for the utilization of clay and clay-based adsorbents are discussed for effective removal of dyes. Based on studies, it was found that the clays (natural and modified) are affective adsorbents for the purification of wastewater containing dyes.
An update on synthetic dyes adsorption onto clay based minerals: A state-of-art review
Dyes are growing to be a problematic class of pollutants to the environment. The disposal of dyes in water resources has bad aesthetic and health effects, hence the need to remove them from the environment. The need for treatment methods that are effective and low in price is rising hence a lot of research interest is being diverted towards adsorbents that are cheap, preferable naturally occurring materials like clays. In most reported dye adsorption studies, limited information on the relationship between characterization results with adsorbent performance on dye removal has been given. This review article seeks to report on the link between the adsorption characteristics of the clays and their adsorption capacities and to gather information on the modifications done on clays to improve their adsorption capacities. A critical analysis of the different mechanisms involved during the decolouration process and their application for dye removal has been discussed in detail in this up-to-date review. From a wide range of consulted literature review, it is evident that some clays have appreciable adsorption capacities on top of being widely available. It was also noted that several parameters like contact time, dosage, concentration, temperature and pH affect the removal of dyes. Furthermore, the application of clay minerals for decolourising water represents economic viable and locally available materials that can be used substantially for pollution control and management. Conclusions were also drawn and suggestions for future research perspectives are proposed.
Removal of Dyes From Wastewater by Adsorption Onto Low-Cost Adsorbents
Impact of Textile Dyes on Public Health and the Environment, 2020
This chapter describes an up-to-date critique of the use of adsorption as a wastewater treatment technique for the removal of dyes. The topics range from the classification of dyes, their occurrence in water and toxicity, various treatment methods, and dye adsorption dynamics onto agricultural wastes and inorganic adsorbents such as clay and metal oxides and adsorption onto microbial biomass under varying operational conditions. It is demonstrated that the discussed materials form alternative adsorbents for dye adsorption from aqueous solutions with comparable or better removal efficiencies relative to the non-renewable coal-based granular activated carbons; they are cheap and abundant. The relative performance of the adsorbents under different environmental parameters for dye removal has also presented. The deductions made and alluded to from various kinetic and adsorption isotherm models are also discussed. The chapter presents the past, present, and suggestions for future conside...
Journal of critical reviews, 2020
Global water pollution caused via dye and pollutants have been reported to need touched an alarming level. These hazardous pollutants pose important threats to ecosystem , humans , due to their carcinogenicity, mutagenicity and toxicity. Different method needed to removal of dyes from waste water, like chemical oxidation, extraction, physical adsorption, electrochemical treatments and zonation. Though, these methods conventional are constrained via little efficiency great cost ,stability, and harmful formation through-produces. Wastewater from production dyestuff is one of the main pollutants water. Different ways have been useful for the remediation of water contaminated. In the present study, the utilize of low-cost, abundantly available, greatly efficient and simply obtained ecofriendly adsorbents like clay and activated carbons have been reported as an alternative to the current expensive ways of dye removal from aqueous solution. .About of the methods depend of the several will yield from (AC). kind of AC is useful: (1) it acts as a dye adsorbent, not only in straight forward methods of the adsorption but too in AC-improved clotting and filtration membrane methods; (2) it strong produces of the oxidizing agents (typically, radicals (_OH)) in electro chemical oxidation dye; (3)it catalysis _OH production in (AOPs); (This reviews kind of clay and AC in dye de-colorization, assesses the possibility of each AC-altered de colorization method and discusses perspectives on future research.
Modified red clays as adsorbents in the removal of cationic dyes from aqueous solutions
Digest Journal of Nanomaterials and Biostructures, 2023
Thermal and thermo-chemical modification methods were applied to a red clay mineral and the resulted products were comparatively studied. The modified clays were characterized by XRD, XRF, UV-vis and FTIR spectroscopy. The adsorption properties towards two cationic dyes, namely methylene blue and crystal violet, were investigated and the effect of initial concentration and contact time was analyzed, revealing superior adsorption properties for the thermo-chemical modified clay. The values of dye removal rate are very high, over 85%, with better adsorption of methylene blue and a competition between dyes as demonstrated by using binary solutions. The best match with the experimental results was obtained for the pseudo-second-order kinetic model.
Treatment of dye-containing effluent by natural clay
Journal of Cleaner Production, 2015
Treatment of dye-containing effluents is a significant challenge because dyes are toxic and pose a threat to the environment. Recent studies have shown that natural clay is able to efficiently remove colour from effluents that contain dyes and various additives. The objective of this study is to investigate the combined effects of dyes, salts and auxiliary chemicals used in the dyeing process, on the adsorption process onto natural clay for the treatment of dye-containing effluents. Batch adsorption experiments were performed using real and synthetic effluents containing dyes (Reactive Red 120, Reactive Orange 84 and Reactive Blue 160), and natural clays (Fouchana and Tabarka). The results show that both of the natural clays are efficient in treating real effluents. Fouchana clay shows a higher efficiency than Tabarka clay in the discolouration of the most colour loaded solution. The added chemical of enzymatic nature (Catalase) facilitates the adsorption of anionic dyes onto clay, likely by electrostatic attraction interaction with the SO 3 groups in the dye, followed by the adsorption onto the clays, of the dye-enzyme system. The mixture of all additives, enhances the adsorption of dyes on the clays, and does not act as a barrier to the decolouration process. Therefore, clays which are inexpensive and effective adsorbents may be promising alternatives for the treatment of the textile dyeing effluents.
Adsorption of Basic Dyes onto Natural Clay
Adsorption Science & Technology, 2004
The adsorption ability of natural clay towards the removal of basic dyes from aqueous textile solutions was investigated. The equilibrium isotherms were measured and analyzed using the Langmuir model and the experimental results compared with the theoretical data. The adsorbent exhibited considerable adsorption capacities of 567, 526, 427 and 300 mg/g towards Neutral Red, Methyl Violet, Methyl Green and Methylene Blue, respectively. Thus, the clay may be used as a cost-effective industrial adsorbent for the removal of basic dyes from industrial effluents.
International Journal of Environmental Monitoring and Analysis, 2015
The aim of the present work is to explore and compare the adsorption capacity of two different clays for removal of textile dye from aqueous solutions. For this purpose, the adsorption of Green Remazole 6B; a reactive dye used in textile industry, was studied in batch mode. The clays used were provided from two different deposits in west of Algeria, one located in Ain-Temouchent (C46) and the other in the region of El Bayadh (C32). Before investigating the adsorption of textile dye, the clays were characterized by various techniques of analysis in order to study all the relevant features. The techniques used are: X-ray diffraction, infrared spectroscopy (IR) and Chemical analysis. Chemical analysis and infrared spectroscopy (IR) show that clays are mainly constituted of alumina and silica in major quantities and other elements in minor quantities. XRD analysis shows that C46 is illite clay, contaning kaolinite, smectite and quartz. On the other hand, C32 is kaolinite clay with prese...
Bentonitic clay as adsorbent for the decolourisation of dyehouse effluents
Journal of Cleaner Production, 2016
Textile dyehouses generate high volumes of coloured wastewaters, which require convenient treatment in order to avoid water bodies' contamination, adverse effects to aquatic life and risks to human health. The complete decolourisation of such contaminated waters in a cost-effective manner is still a challenge nowadays. This work focuses on the use of a clayey material as a low-cost adsorbent for a basic textile dye (Red 46), commonly used in acrylic fibres dyeing. The bentonitic clay (49% of montmorillonite) presents a considerable (50 cmol c /kg) cationic exchange capacity and a porosity of 10%. Dye adsorption kinetics was successfully described by a pseudo-second order model, resulting an average kinetic constant of 0:23 g dye g À1 clay min À1. Adsorption equilibrium was reached in 12e24 h and data were successfully fitted to Freundlich and Langmuir equations. The maximum adsorption capacity predicted by the Langmuir model depends on the pH, varying between 217 mg/g at pH 8 and 584 mg/g at pH 9 (25 C). Increasing the temperature from 25 to 35 C also led to an increase in adsorbed amounts. In addition to the excellent adsorption performance, the clay showed a great affinity to the dye, indicating high propensity to complete decoulorization of textile dyeing wastewaters. The results obtained in the present work show that a natural, readily-available and cheap material i.e. a bentonitic clay can be used as an effective and environmentally-friendly adsorbent for basic dyes.
Enhancing Adsorption Capacity of Clay and Application in Dye Removal from Waste Water
International Letters of Chemistry, Physics and Astronomy, 2014
Natural clay has been considered as a potential absorbent for removing pollutants from water and waste water. Nonetheless, the effective application of clay for water treatment is limited due to small surface area and presence of net negative surface charge, leading to it low adsorption capacity. The absorption capacity was boosted via intercalation of CaO derived from snail shell (SS). The methylene blue sorption potential, PZC, and the surface area of unmodified clay sample were substantially enhanced by the intercalation process. The process of sorption of MB from solution was analyzed using five different isotherm models (Langmuir, Freundlich, Temkin, Harkins-Jura, and Halsey isotherm equations). The value of the Langmuir monolayer sorption capacity qm (mg/g) increased from 50.12 to 88.71, PZC values increased from 4.50 to 7.40, and the surface area (m2/g) value increased from 27 m2/g to 123 m2/g after the intercalation process. The experimental data were fitted into two kinetic...